The decline in antibiotic use has made the treatment of post-implant infections increasingly challenging, especially the problem of bacterial invasion caused by inadequate tissue fusion with the implant in the early stages of the implant. Developing multiple methods to reduce bacterial infections through synergies will be superior to a single model of antimicrobial means.

The composite coating composed of titanium phosphate (TiP)/copper oxide nanoparticles (CuO)/nano-hydroxyapatite (n-HA) named TiP-ua was used to kill Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) under near infrared (NIR) irradiation by means of photothermal therapy (PTT) and photodynamic therapy (PDT) synergism.

The TiP-ua composite coating can reach about 60 °C and produce a certain amount of reactive oxygen species after 15 min irradiation with 980 nm near infrared light with 0.9 W/cm2 power. Under the NIR irradiation of 0.9 W/cm2 power for 10 min, the composite coating can achieve about 90% killing effect on S. aureus and more than 90% killing effect on E. coli. In terms of mouse pre-osteoblasts (MC3T3-E1), TiP-ua showed more superiority in promoting osteogenic differentiation ability. In the mouse infection model, it also showed good antibacterial effect, and could significantly reduce the expression of inflammatory factors and accelerate wound healing. In the bone defect model, the intervention significantly accelerated the regeneration of neobone tissue and enhanced osseointegration capacity.

The experimental results show that TiP-ua coating not only has good photothermal conversion ability, but also has good biosafety, which can accelerate the regeneration and repair of bone tissue around the implant, including accelerating the osteogenic differentiation of cells, and reduce the activity of bacteria to effectively reduce the inflammatory response.

The collaborative antibacterial and bone repair coating in this study has a simple preparation process, high repeatability, high biosafety and positive effect on bone tissue repair, and has great clinical application potential in orthopedics and dental implants.

Near infrared response

Osseointegration

Orthopedic implant

Synergistic antibacterial

© 2025 The Authors. Published by Elsevier B.V. on behalf of Chinese Speaking Orthopaedic Society.